Former FBI Director James Comey slammed Republicans on Monday for not speaking out against President Donald Trump's attacks on the FBI and strongly defended the agency's conduct, following his second round of questioning at a closed-door congressional interview.

"Somebody has to stand up and speak for the FBI," Comey told reporters after his nearly six-hour interview with members of the House Judiciary and Oversight committees. "People who know better, including Republican members of this body, have to have the courage to stand up and speak the truth, not be cowed by mean tweets or fear of their base. There is a truth and they're not telling it. Their silence is shameful."

Comey's comments came after he spent more than five hours behind closed doors on Monday with Republicans and Democrats. He was questioned on the FBI's handling of both the Hillary Clinton email investigation and the Russia investigation.

VIDEO: Comey tells media GOP needs to stand up to Fox News

COMEY blasts House Republicans following his testimony: "Someone has to stand up to the fear of Fox News, fear of their base, fear of mean tweets, stand up for the values of this country & not slink away to retirement. Stand up and speak the truth." pic.twitter.com/Ngqdgmoqdj

"So another day of Hillary Clinton’s emails and the Steele dossier. This while the President ... is lying about the FBI, attacking the FBI and attacking the rule of law in this country. How does that make any sense at all?” -Former FBI Director James Comey https://t.co/ADaa3P7fJopic.twitter.com/tWYNKCHYlR